My Two Dads - S1-E5
Revealing mistake: The third time Elliott exposes herself to a patient (this time to the dead one that Dr. Cox is about to pronounce), you can see quite plainly that she doesn't raise her scrub top enough to reveal her breasts. In fact, the shot is wide enough that if she had, her breasts would have been fully visible on camera.
My Old Lady - S1-E4
Revealing mistake: When the old lady patient is seen "escaping" she lifts the walking frame up out of the hole and it catches the set and lifts it into shot.
Revealing mistake: When Elliot and JD are at the baseball nets, Elliot gets hit by a baseball. If you look closely, particularly in slo-mo, you can see that the ball goes behind her head, and is probably digitally removed from coming out from the other side.
My Old Lady - S1-E4
Revealing mistake: Just before all the bricks fall on JD and it's a surprise, you can see him flinch before they hit him.
Answer: No, it was a fake, they used a stamp.
It is real.